The present invention relates to a configuration control unit for controlling the configuration of a ring LAN, and more particularly to a control system for stopping excessive repetition of a reconfiguration function, and is further capable of preventing a reconfiguration function from being suspended at the time of starting up the system.
As a conventional technique regarding a ring LAN system configuration control system, there is known a technique such as described in Japanese Patent Laid-open Publication JP-A-61-236247.
According to this technique, if a fault occurs on a transmission line, the fault point is disconnected on the assumption that such a fault will continue forever. Thus, in the case where a temporary fault occurs intermittently, such as in the case of breaking of one of twisted pair cables, the fault point is temporarily disconnected from the transmission line. This fault is immediately recovered to obtain a normal state so that the recovered fault point is mounted again on the transmission line. In such a case where a temporary fault occurs intermittently, the above-described conventional technique encounters a problem in that the operations of disconnecting fault points and mounting the recovered fault points on the transmission line must be repeated (hereinafter called "oscillation of reconfiguration function").